Wind turbine manufacturers are constantly making efforts to improve the efficiency of their wind turbines in order to maximise the annual energy production. Further, the wind turbine manufacturers are interested in prolonging the lifetime of their wind turbine models, since it takes a long time and a lot of resources to develop a new wind turbine model. An obvious way to improve the efficiency of the wind turbine, is to improve the efficiency of the wind turbine blades, so that the wind turbine can generate a higher power output at a given wind speed.
WO 01/16482 discloses a blade which is provided with vortex generators arranged in a U-shaped pattern along a line that is convex as seen from the from the trailing edge of the wind turbine blade.
WO 02/08600 discloses a blade which is provided with vortex generators arranged along a line that is parallel to the leading edge on the pressure side of the blade.
WO 2010/100237 discloses a blade which is provided with vortex generators arranged along a straight line.
Accordingly, there is a need for ways to improve the efficiency of new and/or existing blades.